Compressed-gas circuit breaker with readily removable terminal bushing means

ABSTRACT

A high-voltage, high-power compressed-gas circuit interrupter is provided utilizing a grounded metal tank having a gas disposed therein at a relatively low pressure, say, for example 45 p.s.i. A pair of serially related arc-extinguishing units are supported within the metallic grounded tank and utilize a blast of gas directed through an orifice to bring about the extinction of the two series arcs simultaneously. A supporting structure disposed within the tank has lateral supports to properly locate the blast valve and contact housing associated with each arc-extinguishing unit. Additionally, the supporting structure supports an operating cylinder to accommodate a movable piston secured to the moving contact of each interrupter. Terminal bushings are provided at the upper end of the metallic tank and are easily dismantled therefrom by a contact stud and terminal bushing finger arrangement, which easily separates and permits dismantlement at the upper mounting flange portions of the tank for inspection. The high pressure reservoir may be accommodated at the upper end of the tank between the two terminal bushings.

United States Patent [72] Inventors Richard Edmund Kane 3,358,102 l2/l967 Cromer etal 200/148 Monroeville; 3,364,327 l/l968 Cromer ZOO/I48 Robert L. Hess, North Versailles, both of 3,495,057 2/1970 Golota 200/148 Pa.

Primary Exammer-Dav1d SmIth, Jr. 5; 3: Assislanl ExaminerR0bert A. Vanderhye I l e d 1971 AnorneysA. T. Stratton, Clement L. McHale and Willard R. [45] Patente ov. I Crout [73] Asslgnee Westinghouse Electrlc Company Pittsburgh, Pa.

ABSTRACT: A high-voltage, high-power compressed-gas circuit interrupter is provided utilizing a grounded metal tank [54] having a gas disposed therein at a relatively low pressure, say, REA A for exam le 45 p.s.i. A pair of serial] related arc-extin uish- MEANS p y g 7 D F ing units are supported within the metallic grounded tank and Chums rawmg utilize a blast of gas directed through an orifice to bring about [52] U.S.Cl 200/148 R, the extinction of the two series arcs simultaneously. A sup- 174/167 'porting structure disposed within the tank has lateral supports [51] lnt.CI ..l-l0lh33/54, to properly locate the blast valve and contact housing as- H0lh 33/86 sociated with each arc-extinguishing unit. Additionally, the [50] Field of Search 200/148, supporting structure supports an operating cylinder to accoml48.2, 148.6; 174/161, 167, I8 modate a movable piston secured to the moving contact of each interrupter. Rehelences Cited Terminal bushings are provided at the upper end of the metal- UNITED STATES PATENTS lic tank and are easily dismantled therefrom by a contact stud 3,009.042 ll/l96l Schrameck et al. 200/l48.2 x and terminal bushing finger arrangement which easily 3.043940 7/1962 Leeds 200/1482 separates and permits dismantlement at the upper mountmg 3 I29 276 4/1964 Easley ct 3| 200/1482 X flange portions of the tank for inspection. The high pressure 3'29] 12/1966 Telford 2O0/l48 l reservoir may be accommodated at the upper end of the tank 3,284,602 11/1966 Friedrich et al. 200/148 between the lemma hushlhgs- 3 Y9 L I i --H|GH I I PRESSURE I SP GAS H 592w 3e- L 1 LE HIGH PRESSURE INSULATION CLOSE POSITION PATENTEnuuvsolsn 3,624,326

SHEET 1 BF 4 E [5 HIGH 5 PRESSURE SF6 GAS, l6 FOR EXAMPLE LOW PRESSURE FOR EXAMPLE WITNESSES INVENTOR RI h d E. K d

Flg-l R bgr t He s? on PATENTED N0v30 l9?! SHEET 2 BF 4 HIGH PRESSURE SF GAS FOR EXAMPLE HIGH PRESSURE &\\\\\\\\\A\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ m N n Em M SW w mm 76 N CD. 44 l 4 4 H 2 5 Fig. 2

PATENIEU nnvsolsn 3.624.326

SHEET k 0F 4 E2. VALVE 39 fSPOOL ngf msH msToNs \\PRESSURE BE 0v$ 63 j? LOW LOW m ows RE PRESSURE -CLOSTEID OF PTION OF AK BREAKER Fig. 6 Fig. 7

COMPRESSED-GAS CIRCUIT BREAKER WITH READILY REMOVABLE TERMINAL BUSHING MEANS CROSS-REFERENCES TO RELATED APPLICATIONS and also to U.S. Pat. application filed Jan. 21, 1970, Ser. No. 1

4,483 by the same inventors, both applications being assigned to the assignee of the instant application.

BACKGROUND OF THE INVENTION I In a high-power, high-voltage compressed-gas circuit interrupter it is desirable to provide a structure adaptable for fast operation and capable of easy dismantlement for inspection and assembly. Preferably, the structure should be adapted for the use of a number of arc-extinguishing units in series and capable of ready dismantlement. In addition, the structure should be highly efficient in operation and compact in size. Moreover, desirably the number of parts should be reduced to a minimum, and complexities of structure should be avoided.

U.S. Pat. No. 3,154,658 illustrates an arc-extinguishing structure in which a high-pressure blast of gas issues through an orifice or interrupting chamber into the interior of a hollow movable vented contact. It is desirable to utilize such an interrupting structure adaptable for a wide range of voltages and yet to employ simplified structures.

SUMMARY OF THE INVENTION It is a distinct purpose of the present invention to provide a high-power high-voltage circuit breaker structure which is of simplified construction and highly efficient in operation.

According to the preferred embodiment of the invention, there is provided a grounded metallic tank filled with gas at a relatively low pressure. A pair of upstanding terminal bushings bring the current into the tank structure, in which is located a pair of arc-extinguishing units in series. The movable contacts are piston actuated, and the control valve for the pressures used in the operating cylinders is adapted to bring about simultaneous operation of the two serially related arc-extinguishing units. In addition, the preferred embodiment of the present invention utilizes a supporting structure, which not only laterally supports a blast value and stationary contact housing, but also the operating cylinder for the piston effecting movement of the movable contact. This supporting structure, in one particular embodiment, is attached to the upper tank cover so that the entire supporting structure depends from the upper end of the tank.

According to the preferred embodiment, the supporting structure is hollow and serves to conduct high-pressure gas both to the operating cylinder and also to the blast valve and stationary contact housing.

It is a general object of the present invention to provide an improved high-speed compressed-gas circuit interrupter of the metallic grounded tank type.

Another object of the present invention is to provide of an improved compressed-gas circuit interrupter in which an interrupting structure may be laterally supported by a conduit or feed-tubestructure, which, itself, may depend from the upper end of the tank.

Still a further object of the present invention is the provision of an improved circuit breaker structure of the metallic tank type in which dismantlement and assembly of the terminal bushings may be readily achieved in a simplified manner.

Another object of the present invention is the provision of an improved high-voltage high-power compressed-gas circuit interrupter of the dual-pressure type in which the control valve is mechanically actuated and interconnects with other phase units of the device.

Still a further object of the present invention is the provision of an improvdi compressed-gas circuit interrupte of the type utilizing hollow movable contacts supportd in a nov manner and adapted for series relation.

Further objects and advantages will readily become apparent upon reading the following specification taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS.

FIG. I is a vertical sectional view, partially in side elevation, of an improved compressed-gas circuit interrupter embodying the principles of the present invention and illustrated in the O closed-circuit position;

FIG. 2 is an enlarged vertical sectional view taken through the blast valve and contact housing of the device, the contact structure being illustrated in the closed circuit position;

FIG. 3 is a view similar to that of FIG. 2, but illustrating the disposition of the several parts in an intermediate portion of the opening operation;

FIG. 4 is a view similar to FIG. 3, but illustrating the blast valve open and the gas blast extinguishing the arc;

FIG. 5 shows the fully open circuit position of the contact structure with the blast valve closed; and,

FIGS. 6 and 7 illustrate two positions of the control valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a highvoltage high-power compressed-gas circuit interrupter of the dual-pressure type. As shown in FIG. 1, there is illustrated, generally, a grounded metallic tank structure 2 supported upon a foundation 3 and containing interiorly thereof a relatively low-pressure gas 4, such as sulfur hexafluoride (SF gas, at a relatively low pressure, say, for example, 45 p.s.i.

Extending upwardly from the metallic tank structure 2 is a pair of terminal bushings 5, 6 having line conductors 5a, 6a disposed therein, and making separable stud and finger engagement, as at 8, with a pair of stationary nonarcing terminalbushing contacts 9. This permits the terminal bushings 5, 6 to be unbolted at the mounting bolts 11 and the entire terminal bushing structure removed upwardly from the mounting flanges 13 for the tank 2. As shown, the terminal bushings 5, 6 comprise upper caps l5, l6 and interiorly extending conductor studs 5a, 6a, which provide line current to a pair of serially-related arc-extinguishing units, generally designated by the reference numeral 17, and supported laterally from a hollow conduit or high-pressure feed-tube assembly, generally designated by the reference numeral 20.

The lower ends of the terminal bushings S, 6 have metallic mounting flanges such as 5b secured thereto, as by cement, and mounting bolts 11 extending through these mounting flanges and into the cooperating tank flanges 13, the latter being secured, as by welding at 21, to holes 22 provided in the upper end of the tank structure 2.

Situated between the upstanding two terminal-bushings structures 5, 6 is a high-pressure gas reservoir 24, which may contain a suitable high-pressure gas 4, such as sulfur hexafluoride (SF gas, at a pressure, say, for example, 220 p.s.i. Thermal insulation 25 may be provided about the high-pressure reservoir 24 to prevent liquefaction of the high-pressure gas 4 at a low ambient temperature.

Extending downwardly from the high-pressure tank structure 24 is a supporting metal tube 26, which may be secured to a flange 27, itself secured, as by bolts 28, to a supporting flange designated by the reference numeral 29 and secured, as by welding 30, in an opening 31 provided at the upper end of the tank 2. Disposed below the supporting flange 29 is a hollow insulating conduit or feed-tube 32, which has its lower end secured, as by a cemented attachment 33, within a casting 34 having four openings therein. As shown in FIG. I, the lateral openings 34a, 34b are interconnected by laterally extending insulating supports 35, which secure fixedly in position a blast valve and contact housing 36, illustrated more in detail in FIGS. 2-5 of the drawings.

The conduit casting 34 may have a downwardly extending insulating feed-tube 37, which supports a control valve, generally designated by the reference numeral 39, and serving to control the entrance of high-pressure gas to, or an exhausting therefrom, from the bottom of a piston 41, which reciprocates within an operating cylinder 42, and providing movement of a movable tubular vented contact, designated by the reference numeral 44. An electrical tie-bar 42a electrically interconnects the units 17 and assists in supporting the operating cylinders 42. The movable contact 44 makes separable contacting engagement with a relatively stationary contact structure 46, and, during the opening operation of the interrupter 1, draws an are 48 therebetween. This arc 48 is extinguished by a flow of high-pressure gas 4 past a differential blast valve 50 and issuing through an orifice, or an arcing chamber, designated by the reference numeral 52, and directing the flow of high-pressure gas 4 interiorly within the movable tubular vented contact 44.

The operation of the control valve 39 is mechanically secured by an operating rod 54 formed of insulating material, and extending through a seal 55 at the lower end of the tank 2. After passing through the seal 55, the operating rod 54 is mechanically interconnected with the other two tank structures 2, which collectively constitute a three-phase circuit breaker structure. FIGS. 6 and 7 illustrate diagrammatically the pneumatic operation of the control valve 39.

As shown in FIG. 1, it will be apparent that there are provided two circuit-breaker units 17, only one of which is shown, simultaneously actuated and providing two series breaks within the interrupter 1. In the fully open-circuit position of interrupter 1, the movable contacts 44 move downwardly to a position illustrated by the dotted lines in FIG. 1, and designated by the reference numeral 57. Also reference may be made to FIG. in this connection.

During the opening operation, the insulating operating rod 54 moves downwardly and effects actuation of the control valve 39 to exhaust pressure from below the actuating pistons 41, and thereby permit the high pressure gas, existing in the space above the operating pistons 41, to force the pistons 41 downwardly within the operating cylinders 42. This causes both movable tubular contacts 44 to move downwardly separating from the stationary finger contacts 46.

BLAST VALVE AND SEPARABLE CONTACT OPERATION A high-pressure chamber 36 is mounted at some convenient place within the breaker tank 2 and in line with the moving contact 44. This chamber 36 is fitted with a blast valve seat 38 and provides a mounting for the orifice 52. Within the central cavity of the chamber 36 are positioned a spring biased cylindrical blast valve 50. Fixed to the blast valve 50 is a finger contact assembly 47. Between the blast valve 50 and contact follower 45 are mounted two latch assemblies 49, which are located 180 apart. FIG. 2 shows the general arrangement of the parts of the operator with the breaker 1 in the closed posi-' tion. The moving contact 44 is engaged in the finger contacts 47 and the spring biased follower 45 is in contact with the upper end of the moving contact 44. The blast valve 50 is closed. The latches 49 are in their neutral position and held in this position by a wire spring rod 51. FIGS. 3-5 show the sequence of operations of the various parts. When the breaker 1 is starting its opening cycle, the moving contact 44 is extracted from the contact fingers 47. Being spring loaded, the contact follower 45 moves downwardly with the moving contact 44. This movement of the contact follower 45 rotates the latch assemblies 49 by means of teeth 53 provided on the body of the follower 45 engaging the latches 49. This rotation of the latches 49 lifts the blast valve 50 off of its seat 38, and moves it in the opposite direction of the contact follower and moving contact. The contact fingers 47 move with the blast valve 50 as one unit. The second contact hump 56 behind the tip of the finger contact 47 provides a contact point for engagement on the contact follower. Thus the arcing, during interruption, is confined to the tips of the moving contact 44 and contact follower 45 which are lined with arc-resistant material. Once the blast valve 50 is unseated, the high pressure gas behind it causes the blast valve 50 to move rapidly upwardly to its fully open position. The areas exposed to high pressure are arranged such as to have a total force applied to them greater than that of the low pressure side plus the spring loads of the contact follower 45 and blast valve 50. As the blast valve 50 is moving to its fully open position, it engages the stop 59 on the contact follower 45, as shown in FIG. 4 and moves the follower 45 upwardly in the same direction as the blast valve 50. The latches 49 are so designed as to allow the teeth 53 on the follower 45 to ratchet over them in the opposite direction. FIG. 4 shows the blast valve 50 in its fully open position. As the highpressure gas from the blast valve chamber 61 slowly equalizes on the other side of the valve 50 by means of the small gas communication hole 60, the springs on the follower 45 and blast valve 50 overcome the equalizer pressure and move the blast valve 50 and contact follower 45 as a unit downwardly to the closed position as shown in FIG. 5. This is the closed position of the blast valve 50 and also the final position of the contact follower 45 when the breaker l is in the fully open position. When the breaker 1 is again closed, the moving contact 44 engages the contact follower 45 and moves it upwardly to its reset or breaker-closed position, as shown in FIG. 2.

To effect a closing operation of the device, the insulating operating rod 54 is moved upwardly and thereby effects operation of the control valve 39 to place high-pressure gas below the piston 41. This will force the movable tubular contact 44 upwardly into contacting engagement with the relatively stationary contact structure 46, thereby completing the electrical circuit through the circuit breaker 1. The closed circuit position of the device is illustrated in FIG. 1 of the drawings.

From the foregoing description, it will be apparent that there has been provided an improved high-power, high-voltage compressed-gas circuit interrupter involving relatively few parts, and utilizing these parts in a compact manner to provide highly-efficient interrupting conditions to quickly bring about are interruption. The two terminal bushings 5, 6 are readily dismantled from the tank structure 2 by unbolting the mounting bolts 11 securing the flanges 5b, 13 together. The terminal bushing; finger contact assembly 9 and stud arrangement 5a, 6a readily permits such separation of the terminal bushings 5, 6 from the tank structure 2.

It will, moreover, be apparent that there has been provided an improved conduit and supporting system 20 interiorly of the tank structure 2 disposed in depending relationship within the tank structure, and providing a short distance of travel for the high-pressure gas 4. Finally, the utilization of an insulating operating rod 54 mechanically bringing about actuation of the control valve 39 synchronizes the operation of the phase unit A with the adjacent phase units, not shown, which are identical in structure, and having the control valves 39 all mechanically interconnected, as shown.

Although there has been illustrated and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modification may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

What we claim is:

l. A compressed-gas circuit interrupter including a grounded metallic tank having a pair of upper tank flanges encompassing openings provided at the upper end of the grounded metallic tank, a pair of stationary nonarcing terminal bushing contacts disposed adjacent the pair of tank openings, a pair of upstanding terminal bushings having lineconductor studs therein, interrupting means including a pair of separable arcing contacts disposed interiorly within said grounded metallic tank and supported independently of said pair of upstanding terminal bushings, said interrupting means supporting said pair of nonarcing terminal-bushing contacts, the lower ends of the line-conductor studs making substantially linear ready separable contacting engagement with said pair of stationary nonarcing terminal-bushing contacts, whereby a ready disassembly of the terminal bushing may be achieved.

2. The combination of claim 1, wherein a cluster of stationary-contact fingers is associated with each stationary nonarcing terminal-bushing contact.

3. The combination of claim 1, wherein the tank contains a highly efficient arc-extinguishing gas, and each terminal bush- I ing includes an insulating outer shell with gas-communication to the interior of the tank, and each line-conductor stud is spaced radially inwardly from the inner wall of the respective insulating shell.

4. A compressed-gas circuit interrupter including a grounded metallic tank with a pair of spaced upstanding terminal bushings extending upwardly from the upper end thereof through a pair of upper tank openings to accommodate the terminal bushings, a pair of stationary nonarcing terminal-bushing contacts disposed adjacent the pair of tank openings, a high-pressure reservoir located between the pair of spaced terminal bushings externally of the tank, a pair of arc-extinguishing units having separable arcing contacts disposed within the tank and electrically connected in series, a high-pressure supporting conduit assemblage depending downwardly from the upper end of the tank and supported from the upper end of the tank interiorly thereof, said highpressure supporting conduit assemblage supporting said pair of arc-extinguishing units laterally thereof and independently from the terminal bushings, said pair of terminal bushings having line-conductor studs therein, said interrupting means supporting said pair of nonarcing terminal-bushing contacts, and the lower ends of the line-conductor studs making substantially linear ready separable contacting engagement with said pair of stationary nonarcing terminal-bushing contacts, whereby a ready disassembly of the terminal bushings may be achieved.

5. The compressed-gas circuit interrupter of claim 4, wherein each arc-extinguishing unit comprises an operating cylinder and a moving contact piston movable therein, a stationary electrical tie bar supports the lower end of each operating cylinder, and said stationary electrical tie bar is supported at the lower end of the high pressure supporting conduit assemblage.

6. The combination of claim 5, wherein a control valve is located above the electrical tie bar.

7. The combination of claim 6, wherein a pair of high and low-pressure feed tubes extend laterally from the control valve and pneumatically interconnect with the operating cylinder.

8. The combination of claim 4, wherein a high-pressure blast and contact chamber supports the stationary contact structure of each arc-extinguishing unit, and is disposed laterally and supported by said high-pressure supporting conduit assemblage.

9. The combination of claim 5 wherein a high-pressure blast and contact chamber supports the stationary contact structure of each arc-extinguishing unit and is disposed laterally and supported by said high-pressure supporting conduit assemblage.

10. The combination of claim 6, wherein an insulating control-valve rod extends through the lower end of the grounded metallic tank and serves to actuate the control valve.

11. The combination of claim 5, wherein a high-pressure blast and contact chamber supports the stationary contact structure of each arc-extinguishing unit and is disposed laterally and supported by said high-pressure supporting conduit assemblage, and insulating control-valve rod extends through the lower end of the grounded metallic tank and serves to actuate the control valve. 

1. A compressed-gas circuit interrupter including a grounded metallic tank having a pair of upper tank flanges encompassing openings provided at the upper end of the grounded metallic tank, a pair of stationary nonarcing terminal bushing contacts disposed adjacent the pair of tank openings, a pair of upstanding terminal bushings having line-conductor studs therein, interrupting means including a pair of separable arcing contacts disposed interiorly within said grounded metallic tank and supported independently of said pair of upstanding terminal bushings, said interrupting means supporting said pair of nonarcing terminal-bushing contacts, the lower ends of the line-conductor studs making substantially linear ready separable contacting engagement with said pair of stationary nonarcing terminal-bushing contacts, whereby a ready disassembly of the terminal bushing may be achieved.
 2. The combination of claim 1, wherein a cluster of stationary-contact fingers is associated with each stationary nonarcing terminal-bushing contact.
 3. The combination of claim 1, wherein the tank contains a highly efficient arc-extinguishing gas, and each terminal bushing includes an insulating outer shell with gas-communication to the interior of the tank, and each line-conductor stud is spaced radially inwardly from the inner wall of the respective insulating shell.
 4. A compressed-gas circuit interrupter including a grounded metallic tank with a pair of spaced upstanding terminal bushings extending upwardly from the upper end thereof through a pair of upper tank openings to accommodate the terminal bushings, a pair of stationary nonarcing terminal-bushing contacts disposed adjacent the pair of tank openings, a high-pressure reservoir located between the pair of spaced terminal bushings externally of the tank, a pair of arc-extinguishing units having separable arcing contacts disposed within the tank and electrically connected in series, a high-pressure supporting conduit assemblage depending downwardly from the upper end of the tank and supported from the upper end of the tank interiorly thereof, said high-pressure supporting conduit assemblage supporting said pair of arc-extinguishing units laterally thereof and independently from the terminal bushings, said pair of terminal bushings having line-conductor studs therein, said interrupting means supporting said pair of nonarcing terminal-bushing contacts, and the lower ends of the line-conductor studs making substantially linear ready separable contacting engagement with said pair of stationary nonarcing terminal-bushing contacts, whereby a ready disassembly of the terminal bushings may be achieved.
 5. The compressed-gas circuit interrupter of claim 4, wherein each arc-extinguishing unit comprises an operating cylinder and a moving contact piston movable therein, a stationary electrical tie bar supports the lower end of each operating cylinder, and said stationary electrical tie bar is supported at the lower end of the high pressure supporting conduit assemblage.
 6. The combination of claim 5, wherein a control valve is located above the electrical tie bar.
 7. The combination of claim 6, wherein a pair of high and low-pressure feed tubes extend laterally from the control valve and pneumatically interconnect with the operating cylinder.
 8. The combination of claim 4, wherein a high-pressure blast and contact chamber supports the stationary contact structure of each arc-extinguishing unit, and is disposed laterally and supported by said high-pressure supporting conduit assemblage.
 9. The combination of claim 5 wherein a high-pressure blast and contact chamber supports the stationary contact structure of each arc-extinguishing unit and is disposed laterally and supported by said high-pressure supporting conduit assemblage.
 10. The combination of claim 6, wherein an insulating control-valve rod extends through the lower end of the grounded metallic tank and serves to actuate the control valve.
 11. The combination of claim 5, wherein a high-pressure blast and contact chamber supports the stationary contact structure of each arc-extinguishing unit and is disposed laterally and supported by said high-pressure supporting conduit assemblage, and insulating control-valve rod extends through the lower end of the grounded metallic tank and serves to actuate the control valve. 